Phase Diagram and Thermodynamic Properties of the EuBr₂-CsBr Binary System

Phase equilibria in the EuBr2-CsBr binary system were investigated by the differential scanning calorimetry method. The mixing enthalpy of the liquid phase at 1055 K was measured using a Calvet calorimeter over the whole composition range. Two compounds, CsEuBr3, congruently melted at 1034 K, and CsEu3Br7, decomposed at 704 K, were found in the solid phase. Two eutectics were located at x(EuBr2) = 0.197 (T = 812 K) and x(EuBr2) = 0.821 (T = 864 K). The heat capacities of solid and liquid phases of CsEuBr3 were measured from 300 to 1100 K. The CALPHAD method was used to verify the thermodynamic phase compatibility of the system. The Gibbs free energy of formation of solid compounds was calculated.